In a laparoscopic hysterectomy, the body of the uterus is resected from the stump or fundus, and then removed from the operative site. To enable the uterus to be removed through a limited surgical opening, it is desirable to morcellate it into relatively smaller pieces of tissue, which are easier to remove. Our pending patent application, published as WO05/112806 describes an electrosurgical morcellator for the bulk removal of tissue. The present invention relates to an improvement to this type of instrument.
In the device of WO05/112806, a bipolar electrosurgical cutting assembly is provided at the distal end of a tube. The electrosurgical cutting assembly cuts tissue effectively provided that the tissue is in contact with both electrodes. However, as the tissue is cut and a slug of tissue enters the tube, the tissue can become separated from the return electrode making further cutting ineffective. The device of WO05/112806, therefore, has a tissue-grasping instrument connected to the electrosurgical generator, in order to provide an additional return electrode that remains in contact with the tissue as it is drawn into the tube.
While this arrangement works well enough, the connection of the tissue-grasping instrument to the generator does have certain drawbacks. It requires an additional lead to be present between the instrument and the generator, adding to the difficulty in manipulating the instrument. Furthermore, the tissue grasping instrument needs to be provided with a bespoke connector, and this means that the user is not able to use a generic tissue grasper, even if this is preferred.